Torsion spring actuated snap acting electrical switch



Oct. 19, 1965 c. w. HEATH 3,213,227

TORSION SPRING ACTUATED SNAP ACTING ELECTRICAL SWITCH Filed June 10, 1963 INvEN'rQE CLflKEA/cs WILL/7N8 HEHTH,

United States Patent TORSION SPRING ACTUATED SNAP ACTING ELECTRICAL SWITCH Clarence Willans Heath, Bleasby, England, assignor to United-Carr Incorporated, a corporation of Delaware Filed June 10, 1963, Ser. No. 286,779 Claims priority, application Great Britain, July 13, 1962,

p 9 Claims. (Cl. 200-67) ment of the movable contacts relative to the stationary contacts, the actuating element including a first arm portion pivotally mounted on the base, a second arm portion engageable by a switch actuating member, and resilient means connecting adjacent ends of the said arm portions, the arrangement being such that the operation of the switch operating member will cause the resilient means to be stressed or tensioned so as to store up energy which is released after a pre-determined movement of the switch operating member and thereby efiect a rapid pivotal movement of the first mentioned arm portion to move one of the movable contact means into engagement with one of the stationary contacts and move the other movable contact out of engagement with the other stationary contact.

One of the movable contacts may be mounted on the free end of the first arm portion which is pivotally sup ported on the base adjacent its other end.

According to one arrangement, the first and second arm portions and the resilient means comprise integral portions of a strip of spring metal, the resilient means taking the form of an arcuate shaped portion of the strip whose opposite ends are integrally connected to the adjacent ends of the said arm portions.

The first arm portion of the strip may be supported on a contact blade which forms a fulcrum point about which the said arm is adapted to be pivoted, the second arm portion extending over the first arm portion in spaced relation thereto and being formed with a notch or recess for engagement by a lug carried by the switch operating member.

To enable the invention to be fully understood, it will now be described, by way of example, with reference to the accompanying drawing which is a sectional side view of an electrical switch according to one embodiment of the invention.

As shown in the accompanying drawing, the switch is of the single pole changeover type and comprises a base 1, having stationary contacts 2, 3 connected by rivets 4, 5 to wiring terminals 6, 7. A contact blade is provided including a portion 8a projecting from the upper face of the base 1, and a wire attaching portion 8b depending from the lower face of the base.

A housing 9 is mounted on the base and provided with a metal cover 10 formed with integral resilient tongues 11 shaped for snapping engagement in an aperture in a support with which the switch is to be assembled. A switch operating member is provided including a base 12 pivotally mounted by means of pins 13 in opposed side walls of the housing 9, an actuating lug 14 depending from the base 12, and a lever 15 extending upwardly of the cover.

A switch actuating element is provided including a first arm portion 16 carrying the contact 17 at its free end, a second arm portion 18 overlying the first arm and connected thereto by a resilient arcuate shaped portion 19 of generally C shape. Intermediate its ends, the arm portion to provide a recess for receiving the lug 14.

3,213,227 Patented Oct. 19, 1965 ice 16 is pivotally supported on the portion 8a of, the blade contact which serves as a fulcrum for the actuatingelement. The arm portion 18 isbent adjacent its free .end

A metal plate 20 is also pivotally mounted on the portron 8a of the contact blade and is provided with a con- .tact 21, which forms the second movable contact.

As shown, the contact21 isin engagement with the contact 3, and a' circuit is completed-through the wiring terminals 7 and 8b. The contacts 17 and 2 are, howwise about the fulcrum 8:: due to the force of the lug 14 acting downwardly and in a clockwise direction against the bent portion adjacent the free end of the arm 18. This reaction causes a counterclockwise rotationof the arm portion 16, and the first movable contact 17 is brought into engagement with the stationary contact 2 to complete a circuit through the firing terminals 6, 8b. The plate 20 is engaged by the arm portion 16 and is moved simultaneously with the arm portion 16, to disengage the contact 21 from the contact 3.

The contacts 17 and 2 remain engaged only so long as the lever is held depressed, and when it is released, the energy stored in the compressed portion 19 is released to eifect a rapid pivotable movement of the arm portion 16 and the contact 17 away from the contact 2 to break the circuit and return all the other components of the switch to the position illustrated in the drawing, thereby re-establishing the circuit through terminals 5, 8b.

Switches according to the present invention are particularly applicable for cases where a circuit is to be temporarily opened or closed, and one example is in connection with switches adapted to be operated on the opening of a door or the like such as the door of a refrigerator.

I claim:

1. An electric switch comprising a base having a plurality of spaced, stationary contacts mounted thereon, a housing assembled to said base, a plurality of movable contacts disposed within said housing, an actuating element for eifecting the movement of said movable contacts relative to said stationary contacts and a switch operating member pivotably mounted on said housing, said actuating element including a first arm portion pivotably mounted on one of said stationary contacts, a second arm portion engaging said switch operating member and resilient means connecting said first and second arm portions, whereby the operation of said switch operating member will cause said actuating element to pivot in one direction about one of said stationary contacts to move certain of said movable contacts into engagement with certain of said stationary contacts and other of said movable contacts out of engagement with other of said stationary contacts, and said resilient means to be compressed so as to store up energy which on release of said switch operating member will effect a rapid pivotal movement of said actuating element in the opposite direction about said one stationary contact.

2. An electric switch according to claim 1 wherein said first and second arm portions and said resilient means comprise integral portions of a strip of resilient sheet metal, said resilient means comprising an arcuate shaped portion of the strip, the oppositee ends of which are integrally connected to the adjacent ends of said first and second arm portions.

3. An electric switch according to claim 1 wherein one of said movable contacts is mounted on the free end of said first arm portion.

4. An electric switch according to claim 1 wherein one of said movable contacts is mounted on a plate-like support which is mounted so as to be movable simultaneously with said first arm portion to cause the said consaid stationary contacts.

5. An electric switch according to claim 1 wherein said second arm portion is formed with a recess for engagement by a lug forming part of the switch operating member.

6. An electric switch according to claim 1 wherein said housing is provided with fastening means for releasably securing it to a support.

7. An electric switch according to claim 6 wherein said fastening means comprises a plurality of resilient fingers adapted to be snapped into an aperture in a support;

8. An electric switch according to claim 1 wherein said stationary contacts are connected to wire receiving terminals projecting from the side of said base opposite to that to which said stationary contacts are mounted.

'9. An electric switch including a base having multiple stationary contacts mounted thereon, multiple movable contacts, actuating elements for effecting the movement of said movable contacts with respect to said stationary contacts and a switch operating member engaging one of said actuating elements, said actuating elements comprising a first arm pivotably supported by one of said stationary contacts acting as a fulcrum, a second arm in spaced relation to said first arm, having one end engaging said switch operating member and another end integrally connected to said first arm by a resilient arcuate shaped portion and a third arm pivotably mounted on said one stationary contact adjacent said first arm, whereby opera tion of said switch operating member will cause said arms to be pivoted about said one stationary contact to establish a connection between certain of said movable and stationary contacts and break a connection between other of said movable and stationary contacts.

References Cited by the Examiner FOREIGN PATENTS 537,483 12/55 Italy.

BERNARD A. GILHEANY, Primary Examiner.

ROBERT K. SCHAEFER, Examiner. 

1. AN ELECTRIC SWITCH COMPRISING A BASE HAVING A PLURALITY OF SPACED, STATIONARY CONTACTS MOUNTED THEREON, A HOUSING ASSEMBLED TO SAID BASE, A PLURALITY OF MOVABLE CONTACTS DISPOSED WITHIN SAID HOUSING, AN ACTUATING ELEMENT FOR EFFECTING THE MOVEMENT OF SAID MOVABLE CONTACTS RELATIVE TO SAID STATIONARY CONTACTS AND A SWITCH OPERATING MEMBER PIVOTABLY MOUNTED ON SAID HOUSING, SAID ACTUATING ELEMENT INCLUDING A FIRST ARM PORTION PIVOTABLY MOUNTED ON ONE OF SAID STATIONARY CONTACTS, A SECOND ARM PORTION ENGAGING SAID SWITCH OPERATING MEMBER AND RESILIENT MEANS CONNECTING SAIID FIRST AND SECOND ARM PORTIONS, WHEREBY THE OPERATION OF SAID SWITCH OPERATING MEMBER WILL CAUSE SAID ACTUATING ELEMENT TO PIVOT IN ONE DIRECTION ABOUT ONE OF SAID STATIONARY CONTACTS TO MOVE CERTAIN OF SAID MOVABLE CONTACTS INTO ENGAGEMENT WITH CERTAIN OF SAID STATIONARY CONTACTS AND OTHER OF SAID MOVABLE CONTACTS OUT OF ENGAGEMENT WITH OTHER OF SAID STATIONARY CONTACTS, AND SAID RESILIENT MEANS TO BE COMPRESSED SO AS TO STORE UP ENERGY WHICH ON RELEASE OF SAID SWITCH OPERATING MEMBER WILL EFFECT A RAPID PIVOTAL MOVEMENT OF SAID ACTUATING ELEMENT IN THE OPPOSITE DIRECTION ABOUT SAID ONE STATIONARY CONTACT. 